code: def pytest_collection_modifyitems(config, items):
      if config.getoption("--test-slow"):
          return
      skip_slow = pytest.mark.skip(
          reason="Skipped due to the lack of '--test-slow' argument"
      )
      for item in items:
          if "slow" in item.keywords:
              item.add_marker(skip_slow)
  
file_path: prophet/python/prophet/tests/conftest.py
imports: from pathlib import Path
  import pandas
  import pytest
label_desc: Use image node_id 6 for calling a global function with example usage: pytest_collection_modifyitems(config, items) without return types